Calculation of the critical detonation diameter of explosive charges using data on their shock-wave initiation

2006 ◽  
Vol 42 (2) ◽  
pp. 223-226 ◽  
Author(s):  
I. F. Kobylkin
2021 ◽  
Author(s):  
D. Costley ◽  
Luis De Jesús Díaz, ◽  
Sarah McComas ◽  
Christopher Simpson ◽  
James Johnson ◽  
...  

The U.S. Army Engineer Research and Development Center (ERDC) performed an experiment at a site near Vicksburg, MS, during May 2014. Explosive charges were detonated, and the shock and acoustic waves were detected with pressure and infrasound sensors stationed at various distances from the source, i.e., from 3 m to 14.5 km. One objective of the experiment was to investigate the evolution of the shock wave produced by the explosion to the acoustic wavefront detected several kilometers from the detonation site. Another objective was to compare the effectiveness of different wind filter strategies. Toward this end, several sensors were deployed near each other, approximately 8 km from the site of the explosion. These sensors used different types of wind filters, including the different lengths of porous hoses, a bag of rocks, a foam pillow, and no filter. In addition, seismic and acoustic waves produced by the explosions were recorded with seismometers located at various distances from the source. The suitability of these sensors for measuring low-frequency acoustic waves was investigated.


2010 ◽  
Vol 28 (sup1) ◽  
pp. 241-248
Author(s):  
Sergey G. Andreev ◽  
Mikhail M. Boiko ◽  
Natalya V. Paliy

2011 ◽  
Vol 339 ◽  
pp. 379-385 ◽  
Author(s):  
Cheng Bing Li ◽  
Jin Xiong ◽  
Ming Yong Ma

During the perforating and testing combination, the tubing, packer and casing are strongly impacted by shock-wave generated from oil perforators would be damaged. The energy conversion and energy equivalent theories and the underwater explosion energy method are applied to investigate the perforation remnant energy. The theoretical analysis results indicate that the explosion remnant energy of the perforators is the main energy source causing damage of the tubing, packer and casing and the explosion process of the perforators with guns in the oil well can be simplified to the explosion of ordinary explosive charges in the perforation liquid. TNT equivalent and HMX equivalent of perforation remnant energy of three type perforators are obtained by experiments and Cole Formula. Studying results can help to predict dynamic wellbore behaviors and provide a reference for designing the perforation program.


2000 ◽  
Vol 179 ◽  
pp. 193-196
Author(s):  
V. I. Makarov ◽  
A. G. Tlatov

AbstractA possible scenario of polar magnetic field reversal of the Sun during the Maunder Minimum (1645–1715) is discussed using data of magnetic field reversals of the Sun for 1880–1991 and the14Ccontent variations in the bi-annual rings of the pine-trees in 1600–1730 yrs.


Author(s):  
R. Sharma ◽  
B.L. Ramakrishna ◽  
N.N. Thadhani ◽  
D. Hianes ◽  
Z. Iqbal

After materials with superconducting temperatures higher than liquid nitrogen have been prepared, more emphasis has been on increasing the current densities (Jc) of high Tc superconductors than finding new materials with higher transition temperatures. Different processing techniques i.e thin films, shock wave processing, neutron radiation etc. have been applied in order to increase Jc. Microstructural studies of compounds thus prepared have shown either a decrease in gram boundaries that act as weak-links or increase in defect structure that act as flux-pinning centers. We have studied shock wave synthesized Tl-Ba-Cu-O and shock wave processed Y-123 superconductors with somewhat different properties compared to those prepared by solid-state reaction. Here we report the defect structures observed in the shock-processed Y-124 superconductors.


Author(s):  
M.A. Mogilevsky ◽  
L.S. Bushnev

Single crystals of Al were loaded by 15 to 40 GPa shock waves at 77 K with a pulse duration of 1.0 to 0.5 μs and a residual deformation of ∼1%. The analysis of deformation structure peculiarities allows the deformation history to be re-established.After a 20 to 40 GPa loading the dislocation density in the recovered samples was about 1010 cm-2. By measuring the thickness of the 40 GPa shock front in Al, a plastic deformation velocity of 1.07 x 108 s-1 is obtained, from where the moving dislocation density at the front is 7 x 1010 cm-2. A very small part of dislocations moves during the whole time of compression, i.e. a total dislocation density at the front must be in excess of this value by one or two orders. Consequently, due to extremely high stresses, at the front there exists a very unstable structure which is rearranged later with a noticeable decrease in dislocation density.


Author(s):  
Kenneth S. Vecchio

Shock-induced reactions (or shock synthesis) have been studied since the 1960’s but are still poorly understood, partly due to the fact that the reaction kinetics are very fast making experimental analysis of the reaction difficult. Shock synthesis is closely related to combustion synthesis, and occurs in the same systems that undergo exothermic gasless combustion reactions. The thermite reaction (Fe2O3 + 2Al -> 2Fe + Al2O3) is prototypical of this class of reactions. The effects of shock-wave passage through porous (powder) materials are complex, because intense and non-uniform plastic deformation is coupled with the shock-wave effects. Thus, the particle interiors experience primarily the effects of shock waves, while the surfaces undergo intense plastic deformation which can often result in interfacial melting. Shock synthesis of compounds from powders is triggered by the extraordinarily high energy deposition rate at the surfaces of the powders, forcing them in close contact, activating them by introducing defects, and heating them close to or even above their melting temperatures.


Author(s):  
Brynne D. Ovalle ◽  
Rahul Chakraborty

This article has two purposes: (a) to examine the relationship between intercultural power relations and the widespread practice of accent discrimination and (b) to underscore the ramifications of accent discrimination both for the individual and for global society as a whole. First, authors review social theory regarding language and group identity construction, and then go on to integrate more current studies linking accent bias to sociocultural variables. Authors discuss three examples of intercultural accent discrimination in order to illustrate how this link manifests itself in the broader context of international relations (i.e., how accent discrimination is generated in situations of unequal power) and, using a review of current research, assess the consequences of accent discrimination for the individual. Finally, the article highlights the impact that linguistic discrimination is having on linguistic diversity globally, partially using data from the United Nations Educational, Scientific and Cultural Organization (UNESCO) and partially by offering a potential context for interpreting the emergence of practices that seek to reduce or modify speaker accents.


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